Homework is not useless but its quality is far more important than quantity and schools should think very carefully about why they are setting it, an education expert at the University of South Australia says.
Over the past week an anti-homework note sent to parents by a teacher in Forth Worth, Texas, has spread around the world after being posted to Facebook by a parent.
"After much research this summer, I am trying something new," the note from Mrs Brandy Young, which has been shared more than 70,000 times, says.
"Homework will only consist of work that your student did not finish during the school day. There will be no formally assigned homework this year."
The note goes on to say that research has been unable to prove that homework improves student performance.
Instead, Mrs Young urges parents to spend their evenings doing things like reading together, playing outside, and getting their children to bed early, which "are proven to correlate with student success."
Not surprisingly, the note was posted to Facebook with the comment "Brooke is loving her new teacher already!"
Good homework is 'purposeful, specific, and reinforces learning'
However, "she's not quite right," says Brendan Bentley, a PhD candidate and lecturer in the Education Department of the University of South Australia.
In 2006, a review of American research conducted between 1987 and 2003 found that "there was generally consistent evidence for a positive influence of homework on achievement."
The review, led by Dr Harris Cooper of Duke University, found that evidence was stronger for students in grades seven to 12 than for kindergarten to grade six, and for when students, rather than parents, reported how much time they spent doing homework.
On the other hand, in 2013, Australian academics Richard Walker and Mike Horsley published Reforming Homework, in which they reviewed international research and found that for young primary school children, homework is of little or no value and students are regularly given too much.
The issue is that although if you do something more often you get better at it, you have to be doing the right thing in the first place.
"Homework has to be purposeful, specific, and reinforce learning. If it's just to finish work, that may not help the student at all," Mr Bentley said.
In fact, too much homework can be worse than useless: It can be detrimental.
"For students in grades three or four, more than 20 minutes of homework can exhaust them. They go into cognitive load, and their ability to learn goes into a decline," Mr Bentley said.
"They can develop a negative attitude towards learning. It's about getting the balance right."
Cognitive load refers to the total amount of mental effort being used: a heavy cognitive load creates errors or interference.
That 20 minutes is not a guideline for each day: "There needs to be a good argument for having homework every single night," Mr Bentley said.
"Schools have to understand why they are giving homework. Without a good purpose and a rationale: Reconsider it."
He says that homework can be ramped up as students get older, but even in grade 10, research shows that, "if it's more than an hour, it's a waste of time."
Designing effective homework also depends upon how much the student is able to learn.
"Adults can learn about seven things at a time. For young children, that's maybe two or three," Mr Bentley said. "You only need 20 minutes to reinforce that."
However, he says the benefits of homework are not just about reinforcing learning, and that if it does not turn students off, it can teach important study habits.
He agrees that family time and relaxation can be more important than homework.
"Developing good habits and attitudes through interaction with parents can be good — every time you interact with your children, you are teaching assumptions," he said.
On the other hand, too much homework can lead to conflicts with parents.
"Parents are keen for their children to be the best, so they may ask about homework, and may do it for their children, which defeats the purpose," Mr Bentley said.